2020 Volume 36 Pages 23-34
Diatoms are suspended in the atmosphere as fine particles, but their characteristics such as abundance, species composition, source, moving distance, and the weather conditions required for floating remain uncertain. To assess the amount and species composition of diatoms as fine particles in the lower atmosphere, surveys of fine particles were conducted from 4th to 31st August 2019 and from 8th to 31st January 2020 in Hachirogata reclaimed land, Ogata Village, Akita, Japan. The floating diatoms were usually very sparse, generally were dead, and formed a very minor constituent of suspended particulate matter. The abundance of floating diatoms increased under conditions of low solar radiation, high rainfall, and high wind speed. In such conditions, some living soil diatoms were also observed. The mean length of the diatoms in each atmospheric sample obtained was between 32.2 and 41.5 µm. Considering the size-dependent behavior of particles, diatoms probably underwent long-term suspension and/or repeated short-term suspension in the atmosphere.
